Lots of films that I rate highly on this list, but hands down The Right Stuff
(1983).

There seems to be a lot of films listed where the whole plot revolves around NASA and few were it only is a minor part of the film. I would cull the couple options aren't NASA-centric: Men in Black 3
(2012), Transformers: Dark of the Moon
(2011) My Favorite Martian
(1999),Tomorrowland
(2015), Geostorm
(2017)? In some of these movies the NASA link is a single scene or a minor plot point, even though some are listed in Category:Films about NASA - Wikipedia, the connection is very weak.

Movies like Armageddon (1998), Space Cowboys (2000), Contact (1997), Countdown (1967) or Life (2017) would be a far better movies to list as NASA is part of the movies from beginning to end.

I would give some thought to Countdown (1967) a Robert Altman film with James Caan and Robert Duvall, as it was the first major movie about NASA and trailblazed the way for all the other NASA movies. It has a pretty novel plot about NASA going to the moon even before we went two years latter or figured actually how to do it. Plus, it will give some balance with a token older film to the poll. It still gets shown on Turner Classic Movies, so it still has relevance today and is more widely seen than the IMDb votes indicate.